You really need to have the blatantly obvious spelled out to you?
Now, I am going to type this really slowly, so you can understand.
Why is yelling “fire” in a cinema not allowed? Because it could create immediate (I am putting that in bold because it is important) panic that could lead to immediate injury to people in the crowd, due to the ensuing stampede.
Does that t-shirt create an immediate panic? No, it does not.
Does that t-shirt create an immediate scratch that, ANY risk whatsoever of injury among bystanders? cuntingwell bastarding NO. Not in the least.
The most that you could compare this t-shirt to, are holocaust denial, anti-semitic jokes, cripple jokes, racist jokes, or making fun of pearl harbour (which was bloody hilarious, btw.)
SO, calling that t-shirt “worse than shouting ‘fire’ in a crowded cinema”, is asinine, and only serves to showcase how far the propaganda has already infected you.